1. Field of the Invention
This invention generally relates to a bicycle-use measuring apparatus and a control method. More specifically, the present invention relates to a bicycle-use measuring apparatus for a sensor that measures a physical quantity that changes in response to changes in a riding state of a bicycle.
2. Background Information
Japanese Laid-Open Patent Publication No. 2009-006991 discloses a control apparatus for a power meter that measures a power exerted to rotate a bicycle wheel, crank, or other rotating part. As shown in FIG. 10, the control apparatus disclosed in this Japanese Patent Publication comprises a cadence sensor 51, a strain gauge 52, an amplifier 53, an A/D converter 54, a processor 55 and a wireless transmitter 56. The cadence sensor 51 measures cadence (the rotational speed of the crank). The strain gauge 52 measures a strain of the crankshaft occurring when a rider depresses a pedal. The amplifier 53 amplifies an analog electric signal outputted from the strain gauge 52 to a range that can be processed by the A/D converter 40. The A/D converter circuit 54 converts the amplified analog electric signal to a digital signal. The processor 55 calculates the torque acting on the crankshaft based on this digital electric signal. The processor 55 calculates a power imparted by the rider based on this torque and the cadence outputted from the cadence sensor 51. The wireless transmitter 56 transmits the power or torque calculated by the processor 55 to a cycling computer or the like (not shown).